Elastin is an extracellular matrix protein that is primarily found in skin, blood vessels, lung and other tissues and organs that require a degree of elasticity for function. It is formed when lysine residues on tropoelastin molecules become cross-linked with lysine residues on other tropoelastin molecules by lysyl oxidase.
Elastin is expected to be useful in medical applications including tissue repair and restoration and in providing bio-compatible surfaces for medical devices having pre-determined elasticity. In these applications, elastin is generally made by cross-linking the side chains of lysine residues on recombinant tropoelastin molecules using reagents that react with lysine and other charged residues such as glutaraldehyde.
One problem with elastin produced from recombinant tropoelastin is that the cross-linking agents such as glutaraldehyde may be toxic or otherwise cause unwanted tissue reactions or allergy in some individuals. Further, as the elastic properties of elastin tend to be dependent on cross-linking of lysine side chains, there is a limit to the range of elastic properties that elastin can provide. Also, the requirement for cross-linking precludes the effective delivery via some standard administration routes, for example, injection, because without special precaution, the cross-linking agent may cause the elastin to form prior to delivery to the site at which elastin formation is intended.
There is a need for elastic materials that can be formed without use of a cross-linking agent.
There is also a need for compositions that can be administered to tissue by injection to form an elastic material at a site in connection with the site of injection.
There is also a need for elastic materials having elastic qualities not found in elastin or other proteins and bio-materials used for tissue repair, bulking and wound healing.
There is also a need for new formulations for sustained or controlled release of pharmaceutical compounds and tissue factors and for new cell and tissue matrices.